Apparatus for forming containers

ABSTRACT

A packaging machine for individual portions in which a strip of thermoplastic film is automatically releasably gripped along its longitudinally extending marginal portions by rows of gripping elements and while so gripped, the film is moved in a forward direction and is progressively heated by a heater and progressively tautened transversely of its movement as it softens. After leaving the heater and while still gripped, the softened film is positioned over upper mold forms at a cupforming station at one end of the upper run of an endless row of such forms which upper run is moved in said forward direction toward a filling and sealing station successively spaced from said one end. A lower mold form at said cup-forming station is moved against the upper mold form to form the cup-mold and mechanical and suction means forms a plurality of cups in the film after which the marginal grippers and the lower mold form automatically release the film for movement to the filling station where the cups in the film are filled, and the filled cups are then moved to the sealing station while the cups are still in the upper mold forms. At the sealing station a cover sheet is positioned over the cups and is heat sealed to the upper surface of the film around the cup openings during uniform application of pressure against the upper and lower sides of the film at said surface, and finally the film and filled, sealed cups therein are moved out of the upper mold forms and the cups are cut from the film to provide filled and sealed individual packages.

United States Patent [191 Meissner et al.

[ APPARATUS FOR FORMING CONTAINERS [75] Inventors: Konrad E. Meissner, Lafayette;

William A. Lane, Danville; Edwin J. Pelster, Pleasanton, all of Calif.

[73] Assignee: Filper Corporation, San Ramon,

Calif.

[22] Filed: July 5, 1973 [21] Appl. No.: 376,679

Related US. Application Data [62] Division of Ser. No. 208,178, Dec. 15, 1971, Pat. No.

[52] US. Cl 425/347, 425/359, 425/364, 425/387, 425/388, 425/397, 425/400,

425/DIG. 201

[51] Int. Cl. B29c 3/02 [58] Field of Search 425/397, 400, 383, 357

[451 Sept. 241, r974 [57] ABSTRACT A packaging machine for individual portions in which a strip of thermoplastic film is automatically releasably gripped along its longitudinally extending marginal portions by rows of gripping elements and while so gripped, the film is moved in a forward direction and is progressively heated by a heater and progressively tautened transversely of its movement as it softens. After leaving the heater and while still gripped, the softened film is positioned over upper mold forms at a cup-forming station at one end of the upper run of an endless row of such forms which upper run is moved in said forward direction toward a filling and sealing station successively spaced from said one end. A lower mold form at said cup-forming station is moved against the upper mold form to form the cup-mold and mechanical and suction means forms a plurality of cups in the film after which the marginal grippers and the lower mold form automatically release the film for movement to the filling station where the cups in the film are filled, and the filled cups are then moved to the sealing station while the cups are still in the upper mold forms. At the sealing station a cover sheet is p0- sitioned over the cups and is heat sealed to the upper surface of the film around the cup openings during uniform application of pressure against the upper and lower sides of the film at said surface, and finally the film and filled, sealed cups therein are moved out of the upper mold forms and the cups are cut from the film to provide filled and sealed individual packages.

7 Claims, 32 Drawing Figures PAIENTEUSEPMM sum 01 or 1? Pmmwwwm 308mm 782 sum 02 or m palammszm I 318m, 782 v saw ow 0F'17 PIG- -H...

Pmminsimmm sum 05 0F 17 APPARATUS FOR FORMING CONTAINERS This application is a division of copending U.S. application Ser. No. 208,178 filed Dec. 15, 1971, now Pat. No. 3,766,702.

SUMMARY A relatively wide, thermoplastic strip is intermittently drawn past heaters to soften the strip and at the same time the strip is progressively stretched transversely of its length to take up the slack due to expansion, after which and during a stationary interval, a plurality of cup cavities are formed in the softened portion of the strip.

Following the formation of the cups, or cup cavities, the strip is moved to a filling station where the cups are filled.

After filling the cups, the strip is moved to a sealing station where a closure sheet of printed metal foil, coated on the unprinted side with a plastic adapted to adhere to the plastic cup-flim, is drawn from a roll thereof and positioned over the filled cups for sealing to the latter. Individual imprints on the closure sheet are adapted to register with the open side of each cup in the cup-strip and such registration is controlled by an electric eye arrangement past which the closure sheet is moved on its way to said strip.

Following the positioning of the closure sheet over the cups in the cup-film, the sheet is sealed to coplanar marginal portions of the cups, and thereafter the cupfilm and closure strip are moved to a cutting station where the cup-film, filled cup, and closure sheet are die cut to provide individual, sealed, filled cups.

The scrap material is removed to a salvage cutter.

One of the objects of the invention is the provision of a more efficient and reliable machine, and method, for packaging individual portions.

Another object of the invention is the provision of a machine and method whereby the packaging of individual portions of different sizes from a continuous strip of thermoplastic material may be more quickly and economically accomplished than heretofore.

A still further object of the invention is the provision of structure in a machine for forming cups or cavities in a continuous strip of thermoplastic material for receiving a filling material, in which the strip is heated and is stretched and held against sagging due to such heating, during formation of the cavities.

An added object of the invention is the provision of improved means for insuring uniform and complete closing and sealing of individual, filled portions in a plurality of cups in a machine for forming and filling such portions.

Other objects and advantages will appear in the description and drawings.

DESCRIPTION OF DRAWINGS FIG. 1 is a side-elevational view of the machine.

FIG. 2 is a fragmentary isometric view of the film from which the packages are formed including the different stages thereof from forming through filling, covering and separating the individual portions.

FIG. 3 is an isometric view of one of the finished packages.

FIG. 4 is a semi-diagrammatic top plan view, partly in cross-section, of the film feeding portion of the machine adjacent the feed end thereof, separate from the supporting frame.

FIG. 5 is a cross-sectional view along line 5-5 of FIG. 4.

FIG. 6 is a fragmentary top plan view of the frame and driven elements for the film at the feed end of the machine; with the film and portions between the frame being indicated in broken lines.

FIG. 7 is a fragmentary side-elevational view of the elements shown in FIG. 6 including the yieldable hold down elements, with the carrying chains and sprockets shown in broken lines.

FIG. 8 is an enlarged, fragmentary, top plan view of a portion of the film carrying chain assembly as seen from line 8-8 of FIG. 5, with several parts indicated in broken lines.

FIG. 9 is a fragmentary side-elevational view of the portion shown in FIG. 8.

FIG. 10 is an enlarged, fragmentary cross-sectional view along line 10-10 of FIG. 9 showing the film engaging portion in retracted position.

FIG. 11 is a view similar to FIG. 10 showing the film engaging portion in film-engaging position.

FIG. 12 is an enlarged fragmentary plan view, partly in cross section, of a portion of the machine as seen from line 12-12 of FIG. 7 showing the chain tightener.

FIG. 13 is a cross-sectional view of a portion of the film engaging portion approximately as seen from line 13-13 of FIG. 7.

FIG. 14 is an enlarged fragmentary cross-sectional view along line 14-14 of FIG. 5, showing the film over the cup mold.

FIG. 15 is a fragmentary top plan view of a portion of the cup mold.

FIG. 16 is a fragmentary cross-sectional view partly in elevation, along substantially line 16-16 of FIG. 1.

FIG. 17 is an enlarged fragmentary cross-sectional view through the die and mold assembly in separated position at line 17-17 of FIG. 16, for forming a deep cup, and FIG. 18 is a view taken along the same line with the die in a position within the mold.

FIG. 19 is an enlarged cross-sectional view through a portion of a mold form adapted to be substituted for the one shown in FIGS. 17, 18 for forming a larger size cup.

FIG. 20 is a fragmentary cross-sectional view along line 20-20 of FIG. 16.

FIG. 21 is an elevational view of the portion shown in FIG. 16 as seen from line 21-21 of FIG. 16.

FIG. 22 is a fragmentary, enlarged, cross-sectional view of the index drive assembly.

FIG. 23 is a view along line 23-23 of FIG. 22.

FIG. 24 is a view along line 24-24 of FIG. 22.

FIG. 25 is an enlarged, side-elevational view of the filler mechanism.

FIG. 26 is a fragmentary, simplified view of a conventional programmer drive for controlling actuation of the hydraulic and air cylinders associated with different assemblies.

FIG. 27 is a cross-sectional view through the sealing mechanism at the sealing station.

FIG. 27A is a view along line 27A-27A of FIG. 27.

FIG. 28 is a cross-sectional view along line 28-28 of FIG. 27.

FIG. 29 is a cross-sectional view through the cutting assembly.

FIG. 30 is a cross-sectional view along line 30-30 of FIG. 29.

FIG. 31 is a semi-diagrammatic view of the driving train for driving the film and programmer,

DESCRIPTION OF MACHINE Cup Film Carrying Assembly and Heater Referring to FIG. 1, the cup stock comprises a relatively wide strip 1 of thermoplastic material, such as a high impact polystyrene, drawn from a roll 2 at the feed end of the machine, which is the right hand end as viewed in FIG. ll. Roll 2 is on a horizontal shaft 3 that, in turn, is rotatably supported at its ends on stationary supports 4, which supports are rigid with the main frame of the machine, generally designated 5.

Strip I is drawn upwardly from roll 2, successively passing over rollers 6, 7 and then in a generally horizontally extending direction under a roller 8. Said rollers are parallel with each other and are rotatably supported at their ends on main frame 5.

After passing under roller 8, strip 1 extends generally horizontally or forwardly away from the feed or rear end of the machine to a position in which its opposite longitudinally extending marginal portions are over and supported on the inner end portions 9 of horizontally disposed slides that are generally designated I (FIGS 4, 8-11).

The slides 10 are secured on links 13 of a pair of corresponding, endless chains 14, which chains extend at the feed end of the machine over a pair of sprocket wheels I5 (FIG. 5) which are rotatably supported independently of each other on separate stub shafts I6.

Auxiliary side frames generally designated I7 (FIGS. s, 7) extend longitudinally of the machine and strip 1 along opposite sides of said strip 1, and each frame is supported at the feed or rear end of the machine on a vertical post I3 for swinging the opposite ends of the frames Il7 horizontally toward and away from each other. Said opposite ends of frames 17 may be called the forward ends to distinguish from the rear or feed ends. The words forward, forwardly will be used with reference to the direction of movement of the cupfilm I through the machine, which is forwardly.

An adjusting screw 19 extends between the forward ends of the frames 17, which screw is oppositely threaded at its ends in blocks 20 that are pivotally supported on said frames for adjustably spacing the forward ends of the frames from each other upon rotation of the screw in one direction. Locking bolts 21 lock the forward ends of frames I7 in adjusted positions on main frame 5.

The stub shafts I6 carrying sprocket wheels are supported in bearings that, in turn, are on plates 60, which plates are reciprocably supported on the side frames 17 for movement longitudinally thereof for tightening the chains, as will later be more fully described. (FIG. 12)

The upper and lower runs of each chain 14 extend divergently forwardly from sprockets 15 (FIGS. 1, 4) in vertical planes, the upper runs extending over upper sprocket wheels 22 at the forward end of each frame I7, each of which is on a stub shaft 22 rotatably in a bearing supported on the auxiliary side frame 17 adjacent thereto, while the lower runs of the chains 14 extend over lower sprocket wheels 23 spaced below wheels 22 respectively secured on stub shafts 24, each on one of the side frames H7.

The frames 17 are normally adjusted so that they extend divergently relative to each other from their feed ends toward their discharge ends, hence chains 14 and the slides 10 carried thereby will also extend divergentiy relative to each other horizontally along their upper and lower runs from the sprockets ES to the upper and lower sprockets 22, 23.

The lower runs of chains I4 extend slantingly downwardly from sprockets I5, and move downwardly and forwardly away from sprockets i5 when the machine is operated.

Slides 10 are supported on the outer sides of the chains 14 relative to the pairs of sprocket wheels over which the chains extend, hence the slides on the lower runs of the chains are below said runs (FIGS. 841).

The slides III are elongated in a direction transversely of chains I14 and are slotted at 27 (FIGS. It 1 I) for shoulder bolts 28 which, in turn, are secured on brackets 29 secured to the links 13. The heads of the bolts secure the slides to the brackets, each of the slides is movable longitudinally thereof inwardly to the positions 31 indicated in broken lines in FIG. 10, in which positions the marginal portions of the strip I will be supported.

The full line position of one of the slides IQ shown in FIG. 10 is the retracted position while it is below the margin of strip 1 in FIG. 11.

The end portions 9 of slides 10 are the end portions opposite to portions 9, or the outer end portions, and each of said slides has a depending pin 32. The slides are in retracted positions as they move from the lower sprockets 23 upwardly over upper sprockets 22 and over sprockets I5, and before the slides reach the strip 1, a stationary cam 33 on each side frame I7 (FIG. 8) is engaged by pins 32 which move the slides to positions 31 in which the marginal portions of the strips are over said portions 2 as the lower runs of the chains move forwardly.

After the slides are moved to positions 3i at the upper ends of the lower runs of chains I4 they are supported and guided on rollers 34 (FIG. II) on stationary lengths of chains 35 that, in turn, are rigid on stationary supports 36 carried by frames 17. Said slides III are grooved at 37 (FIG. III) to receive the side plates of the links of chains 35 and to thus hold the slides against shifting longitudinally thereof while the marginal portions of the strip I are thereon.

I-Iold-down rails 38 (FIG. 9, Ill) supported on the side frames 17 are positioned over the lower runs of chains 14 and engage the rollers of said chains between the side plates of its respective links I3 to also guide the strips I0 and to hold them in their positions on the rollers 34 of the stationary chain lengths 35.

Positioned between the pair of endless chains 14 is another pair of endless chains 42 that correspond to each other, each chain 42 extending over sprocket wheels 43 at the rear end of the frames t7 (FIG. 5).

Each chain d2 is adjacent to one of the side frames 17 and the sprocket wheels 43 are on stub shafts 44 carried by each frame I7.

Upper and lower sprocket wheels 45, 46 respectively on stub shafts 47, 48 are on frames I7 adjacent the forward ends of said frames and the ends of endless chains 42 at the forward ends of frames I7 extend over said sprocket wheels as, 46. 

1. In apparatus for forming a succession of containers having bottom and side walls in a strip of thermoplastic film at a container-forming station: a. means for supporting said strip for movement in one direction in a path extending longitudinally of said strip to and past said station; b. a mold form at said station having vertically separable upper and lower parts together forming an upwardly opening cavity of the same inside contour as that of the outside contour of a container to be formed; c. said lower part having the inside contour of the outer surface of said bottom wall and part of the side walls, and said upper part having the inside contour of the remainder of said side walls above said part of said lower part; d. said upper part being one of a succession in a row extending longitudinally of said strip, and means for intermittently moving said row of upper parts in said one direction; e. said means for supporting said strip including said row of upper mold parts disposed below said strip; f. means for supporting said lower part of said mold form for upward movement into engagement after each intermittent movement of said succession for forming a complete mold form during the interval between intermittent movements of said row and strip; g. means at said station for drawing the portion of the thermoplastic strip disposed over the open upper end of the mold form downwardly into and against the inside surfaces of said mold form during each of said intervals for forming one of said containers in said mold form when a strip is supported on said row; and h. means connected with said lower part for moving the latter downwardly, at the end of each of said intervals, a sufficient distance to clear the lower part of the container formed in said mold form to permit movement of said row in said one direction to thereby position a succeeding upper part over said lower part for repeating the cycle of operation.
 2. In apparatus as defined in claim 1: i. said upper parts of said mold forms being the upper run of a horizontally extending endless row, and sprockets supporting said endless row for movement of the upper run in said one direction; and j. actuating means operatively connected with one of said sprockets for effecting said intermittent movement, whereby said strip will be intermittently moved in said one direction with said upper mold form under the influence of the containers formed in said mold forms and disposed in said upper parts of said mold forms.
 3. In apparatus as defined in claim 1: i. said means for drawing into a mold form at said station the said portion of the strip extending over the open upper end of a mold form, including means for simultaneously applying air pressure above said portion and evacuating air from beneath said portion.
 4. In apparatus as defined in claim 1: i. said means for drawing into a mold form at said station the portion of the strip extending over the upper open end of a mold form, including means for simultaneously applyiNg a downward mechanical pressure on said portion and evacuating air from beneath said portion.
 5. In a machine for forming containers in plastic sheet material, a. a source of said material in a continuous strip; b. a container-forming station for forming containers in said strip upon movement of said strip to and past said station; c. means for supporting said strip for said movement along a generally horizontally extending path at said station; d. means for intermittently moving said strip longitudinally thereof in one direction along said path; e. container-forming means at said station comprising a mold form having an upwardly opening upper end and sidewalls defining the outside of the open upper end and sidewalls of the container to be formed; f. an overhead member over said mold form at said station, stationery relative to movement in said direction, formed with a downwardly opening cavity vertically aligned over the upper open end of said mold form; g. power actuated means for effecting relative vertical movement between said member and said mold form for engaging the upper and lower sides of said strip by said member and said mold form during the interval between each movement of said strip along said path; h. said member including means for moving the portion of said strip positioned over said mold form at said station into said mold form during the said interval between said movements of said strip; i. said means for intermittently moving said strip including power means connected with said mold form for moving said mold form in said one direction after said portion of said strip has been moved into said mold form whereby said strip will be moved by the engagement between said portion of said strip and said mold form, said portion being part of the container formed at said station.
 6. In a machine as defined in claim 5: j. said means for supporting said strip for movement along said path comprising a succession of mold forms corresponding to said mold form, disposed in a row extending longitudinally of and below said strip; and k. means connecting said mold forms for simultaneous movement in said one direction.
 7. In a machine as defined in claim 6: l. said means connecting said mold forms comprising endless chains supporting said mold forms during movement past said container-forming station; and means supported for movement into engagement with said chains at said station for positioning each mold form at said station in vertical alignment with said overhead member and for holding the mold form so positioned against movement longitudinally of said path during the interval between each of said intermittent movements. 